Light Scattering will be used in two different ways in conjunction with human lenses: a) Scattering from thin sections to obtain structural information, b) Scattering from the whole lens to characterize development aging and cataractogenesis of the lens. Light scattering and other optical measurements on thin lens sections will provide a complete three dimensional mapping of structural elements in the lens. These include: the size, volume fraction and interparticle distance of the protein aggregates and the refractive index difference between the aggregates and their environment; similar four structural parameters obtained describing the properties of the optically anisotropic cytoskeletal components. These measurements will be done on cortical subcapsular etc. cataracts that are unevenly distributed in the lens. Similar mapping will be done on the distribution of the fluorophores both in normal and cataractous lenses. Syneresis as the proposed cause of staracatogenesis will be also investigated by other techniques such as pulse NMR and thermal analysis. The scattering of the whole lens as a function of aging and cataract formation will be also studied. Both unpolarized and polarized (the latter for possible diagnostic purpose) will be used. Attempts will be made to adopt conventional slit lamp instrument to polarized light to see if transitional drug effects can be diagnosed in human lenses.